Copyright Justin Edge Photography

Madison River hatCHES

A Guide To Bugs On The Upper Madison

The Madison River belongs in a special group of rivers, known world wide for its tremendous fishery and stunning scenery. A prolific and productive base of entomological life supports the fishery of the Madison River. A healthy prey base is ultimately what allows us to enjoy our sport. We've put together a chart of what we consider to be the Upper Madison’s most important hatches. It's based on both our experience as well as annual macroinvertebrate surveys conducted by Northwestern Energy as part of their hydroelectric license requirements. These annual surveys are critically important to understanding our hatches. It's really shown us how hatch chart guides are not set in stone. Species assemblages change over time and these annual surveys reflect that. Thus, this hatch chart offers a new way of thinking about our hatches. It will be an adaptable one, updated with each year's data to reflect what's actually occurring with our hatches in real time. Also, while not an exhaustive list, as there are approximately 114 unique taxa of macroinvertebrates on the Upper Madison, we include here the ones that are most prevalent based on annual relative abundances estimated in surveys. Therefore, the bugs listed below are the ones most relevant to current anglers on the Upper Madison. If you're interested in a more specific breakdown of all taxa found in surveys of the Upper Madison check out this blog post.

The Madison River is a strange beast in that it technically is a tailwater, with both a natural dam (Earthquake Lake) and man made dam (Hebgen Lake) upstream, but the shallow and fast flowing nature of the Madison combined with the many contributing tributaries below the dams forces the Madison to lose many of its tailwater characteristics by the time it reaches Ennis. For this reason, I would consider the Madison a hybrid. And the macroinvertebrate surveys reflect this spatial heterogeneity. Assemblages of bugs at the base of Hebgen can be quite different than the suite of available macroinvertebrates near Ennis, for example. This hatch guide provides information on those trends.

The timing marked for each species in this guide err on the wide end. In other words, it incorporates the earliest and latest dates possible. On the one hand it would be pretty convenient to know that the Salmonfly hatch, for example, will always begin on June 25th and last through July 10th year after year without fail. But it’s also part of the mystique that is the Salmonfly hatch, among others. Every year various hatches are slightly different by day from the previous. Generally speaking, biologists tell us the one driving constant that has the biggest impact on timing of hatches is photoperiod length (the amount of daily daylight). Aquatic insects mature as nymphs, or enter pupation from the larval stage, timed to the annual light cycle. Emergence within that window will depend on a variety of environmental conditions such as water temperature, water levels, daily weather, altitude, etc. Everyone has his or her own algorithm or theory, but nothing beats the anticipation of checking the river every morning for your favorite hatch to start!

So let’s dig in to the biggest and most popular aquatic insect hatches on the Upper Madison River relevant to trout fishing!

MAYFLIES

In 3 years time, Mayflies as a group have made a resurgence back from a cyclical low 6% of overall macroinvertebrates on the Upper Madison in 2020 to representing nearly 30% of all aquatic insects in 2023. That's an amazing swing that's been boosting dry fly opportunities for anglers. Mayflies may represent the prettiest and noblest of all aquatic insects. Their beautiful sailboat silhouettes on the water as duns is truly a sight to behold. And lucky for us we have a wide diversity of species on the Upper Madison providing hatches from March until October.

Below are some of the most appropriate Mayfly hatches for the Upper Madison.

Baetis tricaudatus (Common Name: Blue Winged Olive)

Size: #16-24

Color: Highly variable. Olive to brown to gray.

Dry Fly Emergence Time Frame: Year-round with two peaks: April to June and September to October

Click HERE for an image of an Upper Madison Baetis tricaudatus

BWOs are a staple on most western trout streams and the Upper Madison is no different. Within the Batidae family, there are 6 species of BWOs consistently found on the Upper Madison. The most dominant of those is Baetis tricaudatus. In some reaches of the Upper Madison (i.e., near Ennis) this species outnumbers the other BWOs 100 to 1 in recent years. As you progress upriver towards Hebgen, this insect is still very relevant, but becomes less so. It is supplanted in abundance by another BWO (Attenella margarita) which we will cover later. Hatches will typically be in the afternoon hours, and cloudy calm days are a bonus condition. In fact, with a light rain or snow, hatches can last up to a few hours, but on sunny days less so. Nymphs have three tails, but as duns they only have two. This trait can really help you narrow down identification of duns. Color varies wildly, so that alone is not a good reliable trait to identify with, but generally an olive flavor. Most commonly we see these duns in a #16-18 with fall hatches being smaller. Size can also help differentiate between this BWO and the next, smaller BWO. The banner image above is a great example of Baetis tricaudatus on the Upper Madison. A classy bug in spring and fall.

Acentrella turbida/Diphetor hageni (Common Name: Tiny Blue Winged Olive)

Size: #20-24

Color: Highly variable. Olive to brown to gray.

Dry Fly Emergence Time Frame: March to May and August to October

Click HERE for an image of an Upper Madison Acentrella spinner

As the name implies, both of these species are very tiny BWOs. But, functionally, they should look and hatch similarly to their larger cousins. These Tiny BWOs also appear to be more abundant near Ennis than near Hebgen in recent surveys. In fact, by the time you get to Hebgen, this bug is borderline even relevant. As nymphs, duns, and spinners, this insect has two tails. The nymphs have very distinctive dark wingpads on an otherwise mostly pale olive body featuring obvious gills. As duns, body color is mostly olive with a lighter shade near the tails and gray wings. Spinners have clear wings. If you see these tiny versions out and about, your best bet is to locate some slow slick water somewhere to be able to visually see strikes on them better. Despite their size, fish will absolutely key in on them.

Rhithrogena morrisoni (Common Name: March Brown)

Size: 12-14

Color: Brown with olive segmentation highlights. Gray wings speckled with dark venation.

Dry Fly Emergence Time Frame: May

Click HERE for an image of an Upper Madison Baetis tricaudatus

Perhaps one of my favorite hatches to fish is Rhithrogena. This Mayfly is big and elicits big time strikes when they occur. And despite the name (a reference to hatch timing on the east coast), they're more commonly found in May on the Upper Madison. Generally the first week of May. These Mayflies can overlap both with BWOs and Caddis hatches, and you will often see them hatching at the same time on any given day. From annual surveys, we know this Mayfly is far more important near Ennis where it has been very abundant in recent years than near Hebgen where it's been completely absent in survey results! Nymphs of Rhithrogena are very flat, with oval disk like gills on the abdomen. This feature is easily observed by flipping the nymphs over on their backs. Color is reliably brown to olive. As nymphs, they have three tails but as duns and spinners, only two. Duns are stout bodied olive colored with gray wings featuring heavy venation. The only visible difference from duns to spinners is the presence of clear wings. As a late spring hatch, emergence generally occurs mid morning. Both duns and spinners can be present simultaneously.

Ephemerella infrequens (Common Name: Pale Morning Dun PMD)

Size: #14-20

Color: Extremely variable as nymphs from olive to dark brown. Reliably cream pale yellow as Duns.

Dry Fly Emergence Time Frame: June to August

Click HERE for an image of an Upper Madison Ephemerella nymph

PMDs are an often-overlooked species of Mayfly on the Madison River. Overlooked simply due to bad timing. During their emergence time frame, we also have Stoneflies. And on a world famous Stonefly river, these beautiful pale yellow Mayflies just don't get the attention they deserve. PMDs can provide some of the most prolific hatches of the season with some of the most aggressive strikes from rising trout. As the hatch progresses through the season, look for bug sizes of PMDs to get progressively smaller in size. Slow pools are great places to find PMDs. PMD hatches also provide for some great early morning or late evening spinner falls. Many times, if your dry fly offerings are not working but fish are rising, it's likely they're feeding on nymphs in the surface film. Don't ignore the power of an unweighted Pheasant Tail in this situation. In recent years PMDs have become more important further upstream near Hebgen than downstream near Ennis, but both regions have fishable populations. Nymphs can vary wildly in coloration from olive to dark brown. But all color variations still have the same three tails with the same invariable pattern of 2-3 dark bands across the middle of the tails and dark tips. Duns and spinners also have three tails.

Drunella grandis/Drunella coloradensis/Drunella doddsi (Common Name: Green Drake)

Size: #10-12

Color: Pale olive to dark brown

Dry Fly Emergence Time Frame: June to August (Peak in July)

Click HERE for an image of an Upper Madison Drunella nymph and HERE for an adult

Although the Madison River isn’t known for it’s Green Drake hatch, it does have one and they certainly are dense enough to warrant attention in July. Again, the Upper Madison is not a monolith when it comes to its hatches. More of a sliding scale. Drakes gain importance in density as you travel further upriver toward Hebgen. Although present near Ennis, they are fare more abundant near Hebgen according to recent surveys. I often see Drakes out during the tail end of the Salmonfly hatch through the duration of our Golden Stoneflies on the float section of the Upper Madison which probably lends to it going relatively unnoticed much like the PMDs, and is largely concentrated in the section of river known as “between the lakes” (Hebgen and Quake Lake). These super chunky Mayflies remind me of Rhithrogena (March Browns). Just a burly bug. Surveys in the last few years show that Green Drakes are mostly comprised of the species Drunella grandis, followed in importance by Drunella coloradensis and then Drunella doddsi. Emergences are typically mid morning. Both nymphs and duns have three tails.

Callibaetis americanus (Common Name: Callibaetis)

Size: #16-14

Color: Slate gray

Dry Fly Emergence Time Frame: June to September

Click HERE for an image of an Upper Madison Callibaetis adult

In a location like the Madison Valley, the idea of stillwater fishing on a calm sunny day in the middle of summer gets passed up for fishing the 50 mile riffle far too frequently. I understand though. The Upper Madison is a gem. But so are our stillwater lakes (Hebgen, Cliff, Wade, Ennis, and Harrison Lakes). Callibaetis are a (mostly) exclusively stillwater aquatic insect that prefers shallow weed beds. And if Ennis Lake is known for anything, it's shallow weeds. Hebgen gets all the love for it's "gulper" fishing (that distinctive sound large fish make when taking Callibaetis), but here on Ennis, I'd say our Callibaetis fishing is equally good. All three phases (nymph, dun, spinner) of Callibaetis are very important to fish. Nymphs are roughly size #16-18, have three tails, and are brownish gray. They have a noticeable swim pattern of short bursts. As duns, they're roughly #14-16 with slate gray bodies and wings which are speckled. As duns they have only two tails. As spinners the only difference you'll notice from the dun stage is their wings are now clear and they typically lay flat on the water with tails splayed out. Emergence is generally pretty reliable mid morning with spinner falls in the afternoon. The quality of fishing is almost exclusively tied to weather. If the lake is calm, it's on. If there's chop, it's off. Simple as that. Many people get caught in a vortex of chasing risers. It pays to pick a spot and be patient. There's no shortage of bugs or fish and more than likely you'll have plenty of targets to lead with short quick casts right where you are. Keep your false casts to the bare minimum. A pretty reliable fly setup for us is a #14 Adams or Purple Haze with an unweighted Pheasant Tail only 6-8" underneath.

Tricorythodes (Common Name: Tricos)

Size: #18-22

Color: Black and white with spinners turning reddish orange occasionally

Dry Fly Emergence Time Frame: June to September

Click HERE for an image of an Upper Madison Trico adult

Tricos are found throughout the Upper Madison, but seem to be extremely important near Ennis and downstream to Ennis Lake. In recent years, Trico abundance has skyrocketed in Ennis while simultaneously dropping significantly near Hebgen. Is this cyclical? Time will tell. But certainly the river habitat is more conducive to Tricos near Ennis. This is because Tricos thrive in slower currents of rivers with vegetation, and the Madison definitely begins to slow as it passes Ennis and before entering Ennis Lake where one starts encountering heavy weed beds leading into the lake. Tricos can hatch anytime between June and September, but are heaviest July through August on the Upper Madison. Although relatively small in size, Tricos elicit big strikes. As nymphs, duns, and spinners Tricos have three tails with dark brown bodies. As duns, wings are light gray turning to clear as spinners. Emergence can be from afternoon to early morning with males coming off in the afternoon and females in the morning. Those huge swarms of Tricos that are observed in the morning are typically males waiting for females. So, both dun and spinner patterns can be effective at the same time. A #18 Rusty Spinner pattern is a favorite.

Attenella margarita (Common Name: Little Western Blue Winged Olive)

Size: #16-20

Color: Pale cream to dark olive

Dry Fly Time Frame: August to September

Click HERE for an image of an Upper Madison Attenella adult

This smaller version of a BWO hatches in late summer and is becoming increasingly important to the Upper Madison as surveys are showing improving abundance. This is especially the case the further one goes upriver towards Hebgen where Attenella margarita is by far the most dominant Mayfly supplanting the traditionally more abundant and larger Baetis tricaudatus. Thus, as there are fewer overall hatches in late summer when Attenella is hatching, the fact that this species is dramatically increasing in abundance could mean tremendous fall dry fly fishing with small Mayflies near Hebgen. Near Ennis, while abundance has been improving in recent years and certainly relevant to anglers in late summer, Baetis tricaudatus is still the dominant Mayfly here. This insect looks wildly different in color from nymph to dun. The nymphs are mostly pale cream colored with dark bands. As duns, they look like a true BWO, with dark olive bodies and gray wings. Nymphs, duns, and spinners have three tails. The nymphs have a single wide dark band across all three tails. Emergence is more common mid day to afternoon.

This concludes the most important Mayflies on the Upper Madison from recent surveys. However, other notable Mayfly mentions on the Upper Madison which are present in smaller infrequent abundances include:

Epeorus albertae (Pink Lady - Upper Madison spinner HERE)

Serratella tibialis (Hendrickson)

Paraleptophlebia sp. (Mahogany Duns)

Timpanoga hecuba (Red Quill)

Caudatella heterocaudatus

CADDISFLIES

Caddisflies are said to be increasing in importance in Rocky Mountain streams and rivers, supplanting Mayflies as the top aquatic insect on trout menus. Caddisflies are simply a little more resistant to changing environmental conditions. For example, where Mayflies might be sensitive and unable to emerge in warmer and siltier water condition, Caddisflies have showed fewer limitations to these conditions. More particulate matter and plant growth in rivers leads to more Caddisflies. Caddisfly abundance has also been linked to fatter trout, and who doesn’t like that prospect?

And yet they remain the least understood of all aquatic insects by most anglers. Perhaps part of this mystery is attributable to the fact that Caddisflies, as opposed to Mayflies and Stoneflies, have a compete metamorphosis with three stages: Larva, Pupa, Adult. Caddisfly larva have no resemblance to their adult stage. Some Caddis make cases of varying styles (cases, tubes, shell style, etc.) and of varying materials (stone particles, detritus, etc.). Others make no case at all. Free living. So, the wide range of appearances of Caddisflies at the various stages of development can get quite confusing sometimes. Adult Caddisflies, however, come in a wide variety of sizes and colors but they all have the same basic shape: long antennae, short bodies, no tails, and large tent shaped wings held over their backs and extending beyond their bodies.

Although there are nearly two dozen species of Caddisflies on the Upper Madison, we’ll touch on the most abundant and relevant ones here:

Brachycentrus (Common Names: American Grannom/Mother’s Day Caddis)

Size: #12-16

Wing: Grayish brown

Body: Greenish brown to black

Legs: Brown to black

Dry Fly Emergence Time Frame: April to May

Click HERE for an image of an Upper Madison Brachycentrus adult and HERE for an example of a case/pupae

Fly anglers across Southwest Montana look forward each year to the Mother’s Day Caddis hatch, typically occurring in the first few weeks of May during the warmest hours of the day. At this time, the only other sizeable fly available to trout is Rhithrogena, so not a ton of competition for trout's attention. In some years, runoff has already begun and makes fishing the hatch difficult, but sometimes we get lucky and runoff holds off until after the hatch. It’s not uncommon to drive along the river during the thickest part of the hatch and need windshield wipers to clear your view. Certainly a buff is needed on the river unless you want a steady diet of the bug yourself. One interesting behavioral trait of Brachycentrus is they typically do not move much once on the water surface as adults, so be sure to try dead drifting your Elk Hair Caddis first. Historically, Brachycentrus has been as abundant near Ennis as Hebgen but in recent years populations have declined further upstream and strengthened near Ennis. This bug has a tendency of burning hot. Meaning once they start emerging, hatches can be extremely dense for a short period of time then fading fast. It's worth focusing attention in the afternoon and evening when emergence occurs. Brachycentrus are tube case makers. Built out of detritus, they often are rounded tubes where the larvae hide. As such, they aren't likely too important to fish. Pick a rock up next time and find their small cases. If you gently squeeze from the small end, you can pop them out, but not without them gripping to stay inside.

Amiocentrus (Common Name: Little Western Weedy-Water Sedge)

Size: #18-22

Wing: Dark brown

Body: Greenish brown

Legs: Brown

Dry Fly Emergence Time Frame: June to August

Amiocentrus belongs in the same family as Brachycentrus as tube case makers. Slightly smaller than Brachycentrus, Amiocentrus however can emerge in a much wider time frame. Although there appears to be a peak in June and September. These Caddis are prone to inhabit weedy areas of river by attaching their tubes to wavy branches. Perhaps this explains why surveys have found more abundant populations near Hebgen.

Hydropsyche (Common Name: Spotted Sedge)

Size: #12-16

Wing: Brown with mottled light and dark areas

Body: Brownish yellow

Legs: Straw yellow to dark brown

Dry Fly Emergence Time Frame: June to September

Click HERE for an image of an Upper Madison Hydropsyche larva and an adult HERE

Hydropsyche may represent one of the most fishable Caddis hatches to anglers on the Upper Madison (or across the country for that matter) due to it's lengthy hatch timing, multiple species, high relative abundance, and friendly size range. With tan wings and bodies which are light brown to golden in color, all species look similar. Emergence occurs late in the day through dark. This is the time to fish this dominant bug. Females of this net spinner also swim back down to the bottom of the river to deposit eggs, instead of flopping on the water. Interestingly, surveys show that Hydropsyche appears to be improving in abundance near Ennis and diminishing near Hebgen. Due to the life history of the larval stage, it's unlikely that they're significantly important to trout. Hydropsyche are net-spinner Caddis. To me, one of the most amazing critters in the river. These guys make funnel shaped nets out of silk attached to the substrate in such a way as to collect food (organic particulate matter). And in the process, researchers are finding they may be helping the aquatic ecosystem process nutrients like Nitrogen. Watch a cool video here from researchers at MSU studying Hydropsychids.

Helicopsyche (Common Name: Speckled Peter)

Size: #18-22

Wing: Light brown with heavy speckling of dark brown

Body: Pale to straw yellow

Legs: Straw yellow

Dry Fly Emergence Time Frame: June to July

Click HERE for an image of an Upper Madison Helicopsyche cased pupa

If we're talking pure relative abundance, Helicopsyche has all other Caddis beat by a mile on the Upper Madison, especially in the Ennis area. This despite the fact that Helicopsyche aren't even found near Hebgen. What explains this sudden upstream disappearance of an entire taxa, I'm not sure. But the downside to this abundant bug near Ennis is it's small size. Also emerging in the evenings, egg-laying females will be found very near shore and can float for quite a while offering great opportunity to anglers targeting risers. These insects are also case makers. Their cases resemble coils or sea shells which are made out of sand particles. Very small coils to hide in (hence their name). As such, larvae are not likely very important to trout. As with many other Caddis species, both emergence and egg laying occur in the evening, and females will flop on the water attempting to drop eggs. Obviously a great time to fish Caddis.

Glossosoma (Common Name: Little Brown Short-horned Sedge)

Size: #16-18

Wing: Grayish brown

Body: Greenish brown

Legs: Brown

Dry Fly Emergence Time Frame: June to September

Click HERE for an image of an Upper Madison Glossosoma cased pupa and the underside HERE

Glossosoma warrants mention here because of their overall abundance and long season of emergence. Second only to Helicopsyche in the Ennis area, you can expect to find them anytime between May and September. They also are the smallest Caddis you can expect to find on the Upper Madison that are relevant to fishing. Tiny little dark Caddis. Their size somewhat limits opportunities for fishing but you can bet the fish know about them. Glossosoma are interesting in that they live in cases as larvae which are made of pebbles built in a dome shape on the bottom of large boulders. If you flip a rock over near Ennis you're likely to find many barnacle looking objects. These are all individual Glossosoma Caddis. Under the pebbles are the larvae, which shed the domes with each molt. Fascinating critters. They can move around with their home foraging on particulate organic matter until it's time to emerge as adults.

Oecetis (Common Name: Long-horned Sedge)

Size: #14-16

Wing: Straw yellow to brown

Body: Yellow to brown

Legs: Yellow to brown

Dry Fly Emergence Time Frame: June to August

Click HERE for an image of an Upper Madison Oecetis adult

Oecetis would be an otherwise normal looking Caddisfly if not for its single most unique characteristic: super duper long antennae. They're my favorite Caddis for this reason alone. It's so cool. So unique. And in the summer evenings they can be darn fishy too, as adults will spend a lot of time fluttering near the surface. Oecetis often make cases from small pebbles shaped in a tube where they hide. But they're still free moving predators crawling over rocks and debris, and as such are available to trout more so than many other Caddis species as larva They also seem to prefer slow moving sections of river, so these areas may be better places to target during evening emergences and egg laying. Last, according to recent surveys, populations of Oecetis are more abundant near Hebgen than near Ennis.

Cheumatopsyche (Common Name: Little Sister Sedge)

Size: #14-18

Wing: Light to dark brown with faint mottling

Body: Green to greenish brown

Legs: Light to dark brown

Color: Olive body with tan wings

Dry Fly Emergence Time Frame: June to August

As the name Little Sister Sedge implies, this genus is very closely related to Hydropsyche being just a little smaller. So they very closely resemble one another. Cheumatopsychids are also net spinners. On many streams, the Upper Madison included, Cheumatopyche is second only in abundance to Hydropsyche. As opposed to many other Caddis, emergence is more important in this species, which can occur at any time during the day, but low light conditions are prime times and thus evenings are when most emergence occur. As with many species of Caddis, pupa swim to the surface and emerge in open water. However, same as Hydropsyche, females lay eggs on the bottom of the river by swimming back down as adults. Pretty cool.

Lepidostoma (Common Name: Little Brown Sedge)

Size: #14-16

Wing: Brown

Body: Brown to Tan/Yellow

Dry Fly Emergence Time Frame: June to September

The third most abundant Caddis on the Upper Madison near Ennis, Lepidostoma are important in all three major phases: larval drift, emergence, and egg-laying. These Caddis are tube case makers with cases made of sand particles in a circular shape. Daytime to early evening emergence are common.

Arctopsyche (Common Name: Great Gray Spotted Sedge)

Size: #8-10

Wing: Dark gray with light spotting

Body: Greenish brown

Legs: Dark brown

Dry Fly Emergence Time Frame: May to July

Click HERE for an image of an Upper Madison Arctopsyche adult

These are some biguns! Arctopsyche are also net spinning caddis and as such are free living an occasionally available to trout over the course of their two year life cycle. Their distinctive size makes them conspicuous and undoubtedly a target to trout. They also appear to be nearly nocturnal in emergence, making things difficult to take advantage of. As such, the larval form may be a better searching pattern for general nymphing. In recent years, this species is more abundant near Ennis than near Hebgen.

Rhyacophila (Common Name: Green Sedge)

Size: #12-16

Wing: Mottled gray and brown

Body: Olive green

Legs: Brown

Dry Fly Emergence Time Frame: June to August

Click HERE for an image of an Upper Madison Rhyacophila adult

Rhyacophila are a true free living Caddisfly, thriving in fast water as they need the speed of riffles to breath oxygen over their body. They crawl freely over and around rocks on the substrate as predators. Many use a silk strand to sort of rappel from rocks as a safety line. Pretty ingenious. Because they move around so freely, are fairly large, and very conspicuous with their bright green colored abdomens they most certainly are a primary source of food for trout year round. This makes Rhyacophila larva a very good searching pattern any time of year. As for adults, Rhyacophila seem to peak in July evenings. Rhyacophila are only modestly more abundant nearer Hebgen than Ennis. A pretty widespread bug on the Upper Madison.

Dicosmoecus/Onocosmoecus (Common Names: Giant Orange Sedge/Great Late Summer Sedge)

Size: #2-8

Wing: Mottled gray and brown

Body: Reddish orange

Legs: Brownish yellow

Dry Fly Emergence Time Frame: September to October

I link both of these together because they're very closely related. Both extremely large Caddisflies emerge in early fall. A large Caddisfly on the Upper Madison. They are tube case makers, using a matrix of silk, plant, and mineral materials. Perhaps no other bug on the Upper Madison has such disparity between it's importance to trout diets and angler attention. Maybe because it emerges in fall when there are fewer anglers has something to do with this, but it's truly one of the last best secrets. An enormous Caddis with sometimes vibrant orange bodies, they emerge during daytime when there are few other hatches occurring. This makes obvious targets for trout. September/October is the prime month to be on the lookout for the great "October Caddis." Spectacular dry fly fishing with huge Caddis patterns in the afternoon.

STONEFLIES

When one mentions the Upper Madison to an angler, visions of Stoneflies go dancing in their heads. I may be biased, but the Upper Madison is arguably the most famous stream in the world for Stoneflies. Stoneflies have been crawling around stream bottoms for over 250 million years. And with over 600 species, one could spend a lifetime describing them. However, the importance and relevance to the fly fisher is much simpler. Stoneflies need a lot of oxygen and live only in water with good amounts of flow. This is why the Upper Madison is perfect habitat for them. Ten different species of Stoneflies are present on the Upper Madison (Skwalas, 2 species of Goldens, 2 species of Salmonflies, 2 species of Sallflies, 2 species of Little Yellow Stones, and Winter Stones).

Skwala americana (Common Name: Skwala)

Size: 8-12

Color: Dark brown

Dry Fly Emergence Time Frame: March to April

Click HERE for an image of an Upper Madison Skwala adult

Skwala Stoneflies are the first of the larger Stoneflies species to make their emergence in the calendar year on the Madison (excepting the tiny relatively unimportant to anglers winter stones). They're also the most dominant Stonefly taxa as shown in surveys near Ennis, by a mile. This is likely surprising to many who have always thought of the streams near Missoula as the prime destination for this species. The Upper Madison flies under the radar here. Skwalas begin their migrations in late February, with emergence peaking in March and April, and tapering off by June. The key is before runoff. Once Skwalas emerge as adults, they rarely are seen near the water’s surface more than 10 feet out from the bank. If knocked into the water they can scurry with vigor right back to the bank. At first glance during mid to late March you don't see any schucks on the banks, look closer. Unlike their Salmonfly cousins, they rarely hatch from their nymphal shucks on land (e.g., grass, sticks, logs). Instead, they almost exclusively hatch out of shucks just under or on the sides of partially submerged rocks at shoreline. Very similar to Nocturnal Stones. Even a quick glance at the top sides of rocks may not be enough. Flip a few over and you may be surprised at the number of shucks present. Interestingly, adult males have short, non-functioning, almost decorative wings and are incapable of flight. The females are the only ones flying, and with a purpose at that: dispersing eggs on the water surface. Emergence is more active on cloudy days, as with most other aquatic insects. Because Skwalas don’t typically fly much, you need to pay attention a little closer to find them, compared with later emerging Stoneflies. But this is your first chance of the year to get a fish to slap a big dry on the surface. Interestingly, Skwala seems far more important near Ennis when looking at recent surveys. Hardly present near Hebgen, you want to focus your attention near Ennis for this bug.

Pteronarcys californica (Common Name: Salmonflies)

Size: #4-6

Color: Gray brown with orange highlights

Dry Fly Emergence Time Frame: June to July

Click HERE for an image of an Upper Madison Salmonfly nymph and HERE for an adult

The prime rib of trout diets on the Madison River. So much protein stuffed into such a fat, helpless Salmonfly nymph bouncing down the river along a bank, skittering to get liftoff trout. Spending 2-4 years in the cobble as nymphs, they grow to enormous sizes. Similar to Golden Stoneflies, Salmonflies typically start migrating toward shore from May to June and emerging to the excitement of fly anglers all over the Madison Valley, the last week-ish of June as water temps remain in the 50 degree range overnight. Nymphs make their move to the willows to dry out under cover of darkness. Trout, songbirds, and anglers alike stalk them along riverbanks up and down the Madison River as the hatch progresses upstream every day as water temps warm. Looking at recent surveys of this special bug, abundance is much higher the further upstream you go. Perhaps this has to do with the greatest threat to the conservation of Salmonflies: water temp. They require consistently cold temps and with warming trends, we're already seeing range contraction of this iconic bug which should concern us all and focus the mind for cold water conservation. For example, historically Salmonflies were found on the Lower Madison but as water trends have warmed, they're functionally absent now.

Hesperoperla pacifica (Common Name: Golden Stonefly)

Size: #4-8

Color: Dark brown with yellow to gray underbody

Dry Fly Emergence Time Frame: July to August

Click HERE for an image of an Upper Madison Hesperoperla adult

The Golden Stonefly is a staple bug on the Madison River. Typically, migrations of Goldens toward the banks will begin occurring in late June early July. With a 2-3 year life cycle, Golden Stonefly nymphs are in the water 24/7, 365 just like the Salmonfly in a variety of sizes. Another reason to always have an imitation Stonefly nymph handy. Hesperoperla emerge during daytime hours mid to late July and you'll frequently observe them on the banks. There are two common species of Golden Stoneflies found on the Upper Madison. Hesperoperla is far more conspicuous on stream side vegetation than the next species. You'll know it's Hesperoperla by the keyhole shape on their forehead. Forehead markings are critical to identifying western species of Stoneflies. This bug seems pretty equally distributed up and down the Madison.

Classenia sabulosa (Common Name: Nocturnal Stonefly)

Size: #4-8

Color: Dark brown with yellow to gray underbody

Dry Fly Emergence Time Frame: August to September

Click HERE for an image of an Upper Madison Classenia nymphal shuck and HERE for the actual nymph

A second and more sneaky species of Golden Stoneflies is Classenia sabulosa. Sneaky, because locally we refer to them as Nocturnal Stones. They have a propensity for emerging at night. Very abundant especially from McAtee Bridge to below Ennis, a nightly show occurs at dusk and for anglers willing to ply waters early in the AM with big dries on the banks, reward often follows. You'll see evidence of their presence on all the rocks that are partially submerged. The exoskeletons (exuvia) will remain through the day until the wind knocks them off. Their legs are spiny and zebra patterned. You'll know it's Classenia by the characteristic "W" on their foreheads, as nymphs and adults (easily identified on shucks as well). As with Skwala, there's a dramatic decreasing trend in abundance the further upriver you go. Highest densities are in the Ennis reach.

Isoperla (Common Names: Yellow Stones/Yellow Sallies)

Size: #10-12

Color: Yellow

Dry Fly Emergence Time Frame: June to August

Click HERE for an image of an Upper Madison Isoperla nymph

There are several species Yellow Stones on the Upper Madison, and while all can provide occasional excellent dry fly fishing, we've found that emergence is hard to predict, and sporadic at best, and that the nymphal stage is far more productive to mimic. In fact, I suspect this bug is responsible for the reason why bright yellow is such a great color for small nymph imitations. Interestingly, Isoperla does not show up in Northwestern Energy's surveys at either of the long term sites and yet I find them frequently in my own sampling.

MIDGES

Midges are active year round, but are the champion dry fly for winter on the upper Madison largely because they're the only bug typically hatching in winter. With over 30 different species of Diptera on the Upper Madison, they're everywhere. Especially so on cloudy days. A size 20 Z-lon midge, Griffith's gnat, or any other size 18-22 midge pattern will do the trick. Since they're so tiny, and you're usually fishing them on flat light days, I like a pattern like the one above, with a little color post to help me find it on the water. Keep casts relatively short and use your stalking skills to get closer. This will help you find your fly better. Some of the best dry fly fishing of the year is in January and February with Midges.

SCULPINS AND OTHER CRITTERS

Sculpins are in virtually all cobble bottom streams in the west and are abundant in the Madison River. They are present year round. Their habitat is along the bottom of streams and along riverside banks where large cobble provides safety and shelter between darts in and out of protection. Sculpin life cycles last from one to three years. Swimming streamer imitations on the Madison is something to be tried by every fly angler.

Terrestrials

Beetles, ants, and grasshoppers attract not only the open mouths of trout, but fly anglers all over the west to Montana’s waters for “hopper season.” When is hopper season on the Madison River? Beetles, ants, and grasshoppers mature in late summer and early fall. This is typically from mid July to late September when grasses are brown and dry. I haven’t experienced much selectivity among trout when it comes to terrestrials, but aside from hoppers, I’ve typically had more success with ant patterns than any other terrestrial for whatever that’s worth.

Leeches

Leeches live in a wide variety of aquatic environments, but for trout in the Madison River system, they are most important in the stillwater setting such as Ennis and Quake Lakes. This is because their preferred habitats are more readily available in stillwater environments. Those are calm, weedy, and slightly warmer waters. They feed on decaying organic material such as dead vegetative and animal matter.

Leeches also have no specific emergence period. They are active year round. If a body of water is open to fishing, particularly lakes and ponds, you can bet leeches are active and a good choice for imitating.

Crustaceans

For the fly angler, there are three types of crustaceans that should be important: scuds, sow bugs, and crayfish. All are protein rich and sought out by trout when available. Crustaceans have no aerial stage, and thus are not flying around like Mayflies and such. Rather, they’re present in the water constantly, year round. It’s due to this constant presence that crustaceans of all sorts are most important when other aquatic prey species for trout are not: late fall, winter, early spring. Scuds and sow bugs on the Madison aren’t quite as prolific as those on other regional rivers such as the Missouri, but they are still important for the trout diet on the Madison, nonetheless.

Scuds feed on vegetation and decaying detritus. Whenever the fly angler finds patches of weeds in the Madison or Ennis Lake, you can bet scuds and sow bugs are present and worth your attention. This typically occurs the closer one gets to Ennis Lake, where water warms, slows, and vegetation thrives. They usually occur in sizes from #10-16.

Crayfish are omnivorous, eating and scavenging on just about anything that presents itself to them including detrital vegetation and animal matter. Although Crayfish live in all water types, they are more abundant in warmer, slower river reaches where conditions are easier to get around in. Again, this is typically the type of water encountered closer to Ennis Lake. Crayfish can get extremely large near Ennis Lake. It’s not uncommon to see some approaching 6-8” long. Trout are keen to seek out this delicacy, and often times I’ll find Crayfish with their tails eaten off. Crayfish are nocturnal so one should place slightly more emphasis on fishing these imitations at dawn and dusk.

Aquatic Worms

Worms. One of the most ubiquitous aquatic prey species to trout in rivers throughout the world. The Madison River is no different and they are quite abundant, and I can tell you from my own guiding experience, that I rely quite heavily on the worm at times to fool trouts. If a bobber and a nymph are in your future on the Madison River, be sure to pack a San Juan worm in your arsenal.

Upper Madison River Macroinvertebrates